using System;
using System.Data.SqlClient;
using System.Globalization;
using System.Linq;
using System.Threading.Tasks;
using Bit.Billing.Models;
using Bit.Core.Enums;
using Bit.Core.Repositories;
using Bit.Core.Services;
using Bit.Core.Utilities;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;

namespace Bit.Billing.Controllers
{
    [Route("bitpay")]
    public class BitPayController : Controller
    {
        private readonly BillingSettings _billingSettings;
        private readonly BitPayClient _bitPayClient;
        private readonly ITransactionRepository _transactionRepository;
        private readonly IOrganizationRepository _organizationRepository;
        private readonly IUserRepository _userRepository;
        private readonly IMailService _mailService;
        private readonly IPaymentService _paymentService;
        private readonly ILogger<BitPayController> _logger;

        public BitPayController(
            IOptions<BillingSettings> billingSettings,
            BitPayClient bitPayClient,
            ITransactionRepository transactionRepository,
            IOrganizationRepository organizationRepository,
            IUserRepository userRepository,
            IMailService mailService,
            IPaymentService paymentService,
            ILogger<BitPayController> logger)
        {
            _billingSettings = billingSettings?.Value;
            _bitPayClient = bitPayClient;
            _transactionRepository = transactionRepository;
            _organizationRepository = organizationRepository;
            _userRepository = userRepository;
            _mailService = mailService;
            _paymentService = paymentService;
            _logger = logger;
        }

        [HttpPost("ipn")]
        public async Task<IActionResult> PostIpn([FromBody] BitPayEventModel model, [FromQuery] string key)
        {
            if (!CoreHelpers.FixedTimeEquals(key, _billingSettings.BitPayWebhookKey))
            {
                return new BadRequestResult();
            }
            if (model == null || string.IsNullOrWhiteSpace(model.Data?.Id) ||
                string.IsNullOrWhiteSpace(model.Event?.Name))
            {
                return new BadRequestResult();
            }

            if (model.Event.Name != "invoice_confirmed")
            {
                // Only processing confirmed invoice events for now.
                return new OkResult();
            }

            var invoice = await _bitPayClient.GetInvoiceAsync(model.Data.Id);
            if (invoice == null)
            {
                // Request forged...?
                _logger.LogWarning("Invoice not found. #" + model.Data.Id);
                return new BadRequestResult();
            }

            if (invoice.Status != "confirmed" && invoice.Status != "completed")
            {
                _logger.LogWarning("Invoice status of '" + invoice.Status + "' is not acceptable. #" + invoice.Id);
                return new BadRequestResult();
            }

            if (invoice.Currency != "USD")
            {
                // Only process USD payments
                _logger.LogWarning("Non USD payment received. #" + invoice.Id);
                return new OkResult();
            }

            var ids = GetIdsFromPosData(invoice);
            if (!ids.Item1.HasValue && !ids.Item2.HasValue)
            {
                return new OkResult();
            }

            var isAccountCredit = IsAccountCredit(invoice);
            if (!isAccountCredit)
            {
                // Only processing credits
                _logger.LogWarning("Non-credit payment received. #" + invoice.Id);
                return new OkResult();
            }

            var transaction = await _transactionRepository.GetByGatewayIdAsync(GatewayType.BitPay, invoice.Id);
            if (transaction != null)
            {
                _logger.LogWarning("Already processed this invoice. #" + invoice.Id);
                return new OkResult();
            }

            try
            {
                var tx = new Core.Models.Table.Transaction
                {
                    Amount = Convert.ToDecimal(invoice.Price),
                    CreationDate = GetTransactionDate(invoice),
                    OrganizationId = ids.Item1,
                    UserId = ids.Item2,
                    Type = TransactionType.Credit,
                    Gateway = GatewayType.BitPay,
                    GatewayId = invoice.Id,
                    PaymentMethodType = PaymentMethodType.BitPay,
                    Details = $"{invoice.Currency}, BitPay {invoice.Id}"
                };
                await _transactionRepository.CreateAsync(tx);

                if (isAccountCredit)
                {
                    string billingEmail = null;
                    if (tx.OrganizationId.HasValue)
                    {
                        var org = await _organizationRepository.GetByIdAsync(tx.OrganizationId.Value);
                        if (org != null)
                        {
                            billingEmail = org.BillingEmailAddress();
                            if (await _paymentService.CreditAccountAsync(org, tx.Amount))
                            {
                                await _organizationRepository.ReplaceAsync(org);
                            }
                        }
                    }
                    else
                    {
                        var user = await _userRepository.GetByIdAsync(tx.UserId.Value);
                        if (user != null)
                        {
                            billingEmail = user.BillingEmailAddress();
                            if (await _paymentService.CreditAccountAsync(user, tx.Amount))
                            {
                                await _userRepository.ReplaceAsync(user);
                            }
                        }
                    }

                    if (!string.IsNullOrWhiteSpace(billingEmail))
                    {
                        await _mailService.SendAddedCreditAsync(billingEmail, tx.Amount);
                    }
                }
            }
            // Catch foreign key violations because user/org could have been deleted.
            catch (SqlException e) when (e.Number == 547) { }

            return new OkResult();
        }

        private bool IsAccountCredit(BitPayLight.Models.Invoice.Invoice invoice)
        {
            return invoice != null && invoice.PosData != null && invoice.PosData.Contains("accountCredit:1");
        }

        private DateTime GetTransactionDate(BitPayLight.Models.Invoice.Invoice invoice)
        {
            var transactions = invoice.Transactions?.Where(t => t.Type == null &&
                !string.IsNullOrWhiteSpace(t.Confirmations) && t.Confirmations != "0");
            if (transactions != null && transactions.Count() == 1)
            {
                return DateTime.Parse(transactions.First().ReceivedTime, CultureInfo.InvariantCulture,
                    DateTimeStyles.RoundtripKind);
            }
            return CoreHelpers.FromEpocMilliseconds(invoice.CurrentTime);
        }

        public Tuple<Guid?, Guid?> GetIdsFromPosData(BitPayLight.Models.Invoice.Invoice invoice)
        {
            Guid? orgId = null;
            Guid? userId = null;

            if (invoice != null && !string.IsNullOrWhiteSpace(invoice.PosData) && invoice.PosData.Contains(":"))
            {
                var mainParts = invoice.PosData.Split(',');
                foreach (var mainPart in mainParts)
                {
                    var parts = mainPart.Split(':');
                    if (parts.Length > 1 && Guid.TryParse(parts[1], out var id))
                    {
                        if (parts[0] == "userId")
                        {
                            userId = id;
                        }
                        else if (parts[0] == "organizationId")
                        {
                            orgId = id;
                        }
                    }
                }
            }

            return new Tuple<Guid?, Guid?>(orgId, userId);
        }
    }
}